|
Trucidocynodon Riograndensis
''Trucidocynodon'' is an extinct genus of ecteniniid cynodonts from the Upper Triassic (Carnian) of Brazil. It contains a single species, ''Trucidocynodon riograndensis''. Fossils of ''Trucidocynodon'' were discovered in outcrops of the Upper Santa Maria Formation in Paleorrota Geopark, Agudo, Rio Grande do Sul, Agudo. ''Trucidocynodon'' is one of the most completely known Triassic cynodonts, as its holotype is a nearly complete and fully articulated skeleton. Description ''T. riograndensis'' was a carnivorous cynodont closely related to ''Ecteninion lunensis'' and ''Diegocanis, Diegocanis eleganus'', from the Upper Triassic Ischigualasto Formation of Argentina. It differed from other ecteniniids in several respects, including its larger size. The holotype skeleton has a skull around in length and a total body length of around . The holotype, UFRGS PV-1051-T, is accessioned at the Federal University of Rio Grande do Sul (UFRGS) alongside four Paratype, paratypes based on post ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. The corresponding series (stratigraphy), series of rock beds is known as the Upper Triassic. The Late Triassic is divided into the Carnian, Norian and Rhaetian Geologic time scale, ages. Many of the first dinosaurs evolved during the Late Triassic, including ''Plateosaurus'', ''Coelophysis'', ''Herrerasaurus'', and ''Eoraptor''. The Triassic–Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. Etymology The Triassic was named in 1834 by Friedrich August von Namoh, Friedrich von Alberti, after a succession of three distinct rock layers (Greek meaning 'triad') that are widespread in southern Germany: the lower Buntsandstein (colourful ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourth-largest country in the Americas, and the List of countries and dependencies by area, eighth-largest country in the world. Argentina shares the bulk of the Southern Cone with Chile to the west, and is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south. Argentina is a Federation, federal state subdivided into twenty-three Provinces of Argentina, provinces, and one autonomous city, which is the federal capital and List of cities in Argentina by population, largest city of the nation, Buenos Aires. The provinces and the capital have their own constitutions, but exist under a Federalism, federal system. Argentina claims sovereignty ov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Prehistoric Animal Genera
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. Theoretical implications Monotypic taxa present several important theoretical challenges in biological classification. One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs a distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical system. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecteniniidae
Ecteniniidae is an extinct family of probainognathian cynodonts from the Triassic of South America. They are notable for their large size, as well as for being among the first synapsids with specializations towards cursoriality. Phylogeny Below is a cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ... from Martínez ''et al.'' (2013): References Probainognathia Late Triassic first appearances Late Triassic extinctions Prehistoric therapsid families Triassic animals of South America {{paleo-cynodont-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Therapsids
This list of therapsids is an attempt to create a comprehensive listing of all Genus, genera that have ever been included in the Therapsida excluding mammals and purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (''nomen dubium, nomina dubia''), or were not formally published (''nomen nudum, nomina nuda''), as well as synonym (zoology), junior synonyms of more established names, and genera that are no longer considered therapsids. The list currently contains 510 generic names. Naming conventions and terminology Naming conventions and terminology follow the International Code of Zoological Nomenclature. Technical terms used include: * Synonym (zoology), Junior synonym: A name which describes the same taxon as a previously published name. If two or more genera are formally designated and the type (zoology), type specimens are later assigned to the same genus, the first to be published (in chronological o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ungulate
Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined to be a polyphyletic and thereby invalid clade based on molecular data. As a result, true ungulates had since been reclassified to the newer clade Euungulata in 2001 within the clade Laurasiatheria while Paenungulata has been reclassified to a distant clade Afrotheria. Living ungulates are divided into two orders: Perissodactyla including Equidae, equines, rhinoceroses, and tapirs; and Artiodactyla including Bos, cattle, antelope, Sus (genus), pigs, giraffes, camels, Ovis, sheep, deer, and Hippopotamidae, hippopotamuses, among others. Cetaceans such as Whale, whales, Dolphin, dolphins, and Porpoise, porpoises are also classified as artiodactyls, although they do not have hooves. Most terrestrial ungulates use the hoofed tips of their toes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cursoriality
A cursorial organism is one that is adapted specifically to run. An animal can be considered cursorial if it has the ability to run fast (e.g. cheetah) or if it can keep a constant speed for a long distance (high endurance). "Cursorial" is often used to categorize a certain locomotor mode, which is helpful for biologists who examine behaviors of different animals and the way they move in their environment. Cursorial adaptations can be identified by morphological characteristics (e.g. loss of lateral digits as in ungulate species), physiological characteristics, maximum speed, and how often running is used in life. Much debate exists over how to define a cursorial animal specifically. The most accepted definitions include that a cursorial organism could be considered adapted to long-distance running at high speeds or has the ability to accelerate quickly over short distances. Among vertebrates, animals under 1 kg of mass are rarely considered cursorial, and cursorial behaviors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapsids
Synapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant reptiles and therefore, birds). Unlike other amniotes, synapsids have a single temporal fenestra, an opening low in the skull roof behind each eye socket, leaving a zygomatic arch, bony arch beneath each; this accounts for the name "synapsid". The distinctive temporal fenestra developed about 318 million years ago during the Late Carboniferous period, when synapsids and sauropsids diverged, but was subsequently merged with the orbit in early mammals. The basal (phylogenetics), basal amniotes (reptiliomorphs) from which synapsids evolved were historically simply called "reptiles". Therefore, stem group synapsids were then described as mammal-like reptiles in classical systematics, and non-therapsid synapsids were also referred to as pelyco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digitigrade
In terrestrial vertebrates, digitigrade ( ) locomotion is walking or running on the toes (from the Latin ''digitus'', 'finger', and ''gradior'', 'walk'). A digitigrade animal is one that stands or walks with its toes (phalanges) on the ground, and the rest of its foot lifted. Digitigrades include birds (what many see as bird's knees are actually ankles), cats, dogs, and many other mammals, but not plantigrades (such as humans) or Ungulate, unguligrades (such as horses). Digitigrades generally move more quickly than other animals. There are structural differences between the Limb (anatomy), limb anatomy of plantigrades, unguligrades, and digitigrades. Digitigrade and unguligrade animals have relatively long carpals and tarsus (skeleton), tarsals, and the bones which correspond to the human ankle are thus set much higher in the limb than in a human. In a digitigrade animal, this effectively lengthens the foot, so much so that what are often thought of as a digitigrade animal's "hands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biomechanics
Biomechanics is the study of the structure, function and motion of the mechanical aspects of biological systems, at any level from whole organisms to Organ (anatomy), organs, Cell (biology), cells and cell organelles, using the methods of mechanics. Biomechanics is a branch of biophysics. Etymology The word "biomechanics" (1899) and the related "biomechanical" (1856) come from the Ancient Greek βίος ''bios'' "life" and μηχανική, ''mēchanikē'' "mechanics", to refer to the study of the mechanical principles of living organisms, particularly their movement and structure. Subfields Biofluid mechanics Biological fluid mechanics, or biofluid mechanics, is the study of both gas and liquid fluid flows in or around biological organisms. An often studied liquid biofluid problem is that of blood flow in the human cardiovascular system. Under certain mathematical circumstances, blood flow can be modeled by the Navier–Stokes equations. ''In vivo'' whole blood is assum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesozoic
The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian reptiles such as the dinosaurs, and of Gymnosperm, gymnosperms such as cycads, ginkgoaceae and Araucariaceae, araucarian conifers; a hot Greenhouse and icehouse earth, greenhouse climate; and the tectonic break-up of Pangaea. The Mesozoic is the middle of the three eras since Cambrian explosion, complex life evolved: the Paleozoic, the Mesozoic, and the Cenozoic. The era began in the wake of the Permian–Triassic extinction event, the largest mass extinction in Earth's history, and ended with the Cretaceous–Paleogene extinction event, another mass extinction whose victims included the non-avian dinosaurs, Pterosaur, pterosaurs, Mosasaur, mosasaurs, and Plesiosaur, plesiosaurs. The Mesozoic was a time of significant tectonic, climatic, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Probainognathia
Probainognathia is one of the two major subgroups of the clade Eucynodontia, the other being Cynognathia. The earliest forms were carnivorous and insectivorous, though some groups eventually also evolved herbivorous diets. The earliest and most basal probainognathian is the Middle Triassic (Anisian) aged ''Lumkuia'', from South Africa, though probainognathians would not become prominent until the mid Norian stage of the Late Triassic. Three groups survived the Triassic–Jurassic extinction event, extinction at the end of Triassic: Tritheledontidae and Tritylodontidae, which both survived until the Jurassic—the latter even into the Cretaceous (''Montirictus'' and ''Xenocretosuchus'')—and Mammaliaformes, which includes the mammals. Phylogeny Below is a cladogram from Ruta, Botha-Brink, Mitchell and Benton (2013) showing one hypothesis of cynodont relationships: Cladogram from Stefanello ''et al.'' (2023): See also * Evolution of mammals * List of prehistoric mammals Refe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
